In the late afternoon yesterday (February 13, 2011) sunspot 1158 released a decent-sized solar flare, a magnetic eruption on the Sun. This was classified as an M6.6 flare, which is above average in explosive energy, but hardly up to the nastiness we experienced in late 2003 when the Sun was throwing an epic hissy fit.

The image here is from the Solar Dynamics Observatory, and shows the sunspot in the extreme ultraviolet part of the spectrum. This is the first solar flare sending energy toward the Earth since the Sun started its magnetic cycle up again last year. That may sound scary, but we’ll be OK. First of all, it’s not all that big a flare. Second, the effect comes in two ways: through electromagnetic energy (light), and subatomic particles. The first is already over, and the second will be buffered by the Earth’s magnetic field.

Here’s how this works: the Sun’s magnetic field is extremely complicated, with lots of magnetic field lines embedded in packets of ionized gas (called plasma) that rise and fall beneath the surface. These field lines can pierce the Sun’s surface, loop up, and then come back down to create a complete circuit (as you can see in the SDO pic above; the plasma follows the field lines and glows). All these field lines can get tangled up, like a sack full of stretched springs, and there’s a huge amount of energy that can be stored in these magnetic fields. If one of them suddenly connects with another it can release its energy, snapping other lines… and you get an enormous cascading release of energy. Boom! Solar flare.

Sometimes vast energies are released this way; some huge flares have blasted out 10% the energy of the entire Sun! This latest one was very mild compared to that though.

When the explosion occurs, the blast moves upward into space, sending out a wave of subatomic particles moving at speeds of upwards of millions of kilometers per hour. There can also be a flash of extremely high-energy gamma rays. Those are photons of light, like visible light but vastly more energetic. They move out at the speed of light (of course, since they are light!). So when an observatory like SDO spots a flare, the gamma rays are already here. Happily, those get absorbed by our atmosphere, and really don’t pose a threat to us on the ground.

However, in space things are different. Those gamma rays can hit satellites and send a flood of fast electrons through the circuitry, frying the electronics. Also, the wave of subatomic particles follows hours or days later, hits our Earth’s magnetic field, and can also cause havoc in satellites. If the wave is big enough it can even cause blackouts here on Earth!

Of course, that’s why we have SDO and other satellites observing the Sun. We can see this coming and take measures to minimize the effects. Shut down vulnerable satellites, redirect power on Earth to lower the strain on the grid, and so on. This particular flare doesn’t seem to be causing much distress according to the Space Weather Prediction Center (here in Boulder), but there might be some nice aurorae if you live at an extreme north or south latitude. Keep your eyes open for that tonight!

I’ll also note that, via reddit, I learned of a website that is making all sort of goofy weather predictions because of this flare. I can’t state categorically that flares don’t affect our weather, but if they do it is in such a minuscule way that it’s very difficult to correlate the two. That site was talking about increased rainfall in Europe from the flare, which is simply nonsense. And I also don’t think you need to worry about superstorms, either.

As the Sun’s magnetic cycle ramps up over the next couple of years, solar astronomers will be keeping track of what’s what. We have several satellites watching our star with unblinking eyes, and if there’s any cause for actual worry, you’ll hear about it from reliable source like SpaceWeather and Universe Today. And I might have a thing or two to say as well.

We don’t have to worry about solar flares on Earth , because of the Earths magnetic field. But if we ever colonise the Moon this will be a main concern because the Moon is outside the Earths magnetic field so the personal of a Moon base would have to keep watch on the Sun and take shelter deep under the Moon surface if a flare occurs . In fact in the novel Space by James Micthner a fictonal Apolo mission ends when two Astronuts are killed on the Moons surface by a solar flare. The thrid piolts the CSM back to Earth allone. (By the way Space is a good book read it )

I have an environmental activist in my head who is chastising us for what we have done to the Sun and blames us for the magnetic cycle ramping up over the next few years. I know that this makes no sense. The environmental activist in my head is an amalgam of over-the-top stereotypes. He eats only raw fruit, is quite shrill and does not salt his sidewalk in winter, too.

What about the ISS?
Will the astronauts have to retreat a better shielded section (“storm shelter”), when (if) the subatomic particles arrive?
Were they hit by the gamma rays?
How good are they shielded against that, and what effects will the remaining dosage have that always gets through the shielding?

This brings to mind a part of Death From The Skies that really stuck with me (Heck, I’ve seen the phrase in question in many books, too). I’ll post it here, with apologies to Phil – of course, if it’s not kosher to post material from your books, please delete it right away and let me know! Sorry and thanks

An occupational hazard of being an astronomer is getting free astronomy textbooks in the mail. Like e-mail spam (but tipping the scale at ten pounds), they come unannounced, and generally wind up in used bookstores collecting dust (the real-world equivalent of the spam filter).

I can’t resist thumbing through them. I torture myself this way, knowing that I’ll find some odd chapter arrangement, some scientific error, some small turn of phrase that will irk me in some way. Invariably, there will be some permutation of this sentence, “The Sun is an ordinary, average star.”

If you decide to read only this chapter and then close this book forever, then please walk away with just one thing: the Sun is a star, with all that this implies. The sun is a mighty, vast, furiously seething cauldron of mass and energy. The fires in its core dwarf into microscopic insignificance all the nuclear weapons ever built by mankind. A million earths would be needed to fill its volume, and the light it emits can be seen for trillions upon trillions of miles. Invisible forces writhe and wrestle for control on its surface, and when it loses its temper, the consequences can be dire and even lethal.

Watch out! I can foresee Media Fail Part III when various sites quote Phil as saying:

“In the late afternoon yesterday (February 13, 2011) sunspot 1158 released a decent-sized solar flare, a magnetic eruption on the Sun. This was classified as an M6.6 flare, which is above average in explosive energy…and you get an enormous cascading release of energy. Boom! Solar flare….Those gamma rays can hit satellites and send a flood of fast electrons through the circuitry, frying the electronics….Keep your eyes open for that tonight!…I’ll also note…all sort of goofy weather…because of this flare… increased rainfall in Europe…you need to worry about superstorms.”

“Scientists may soon be able to prove the existence of the gas giant, which could be four times the size of Jupiter, according to astrophysicists John Matese and Daniel Whitmire from the University of Louisiana at Lafayette. The two first proposed Tyche’s existence in order to explain a change in path of comets entering the solar system, according to The Independent.”

Given HuffPo’s record I wouldn’t trust them if they said the sky was blue. How accurate is this report?

Any word about the effect on wireless/WiFi? I’ve known about flares affecting satellite internet for years (there’s a reason why satellite internet should only be for times when you can’t use anything else), but I’ve heard rumour that big enough flares can wreak havoc on mobile networks and WiFi.

Well, In 2003 that hissy fit wasn’t aimed directly at earth. They were over the limb. I agree they we’re massive flares X-18 to X-45 if I remeber correctly but we(the earth) were not in their path yet we had effects anyway. As of 10:30pm on 2-14-11 an X-2.2 was hurling our way. The Sun is not finished yet as they expect more. Yes, from Spaceweather.com and NOAA. What I find most interesting is I looked for posssible blackouts because of the new flare as well as the coronal hole effects we are currently under as that would cause geoeffective events and found that many utilities have decided they were gonna have planned blackouts tomorrow and service this week. Curious as that is what would be needed to protect the grid. For anyone who would like to check out the status of the sun..try spaceweather.com and Space weather now as well as Today’s Space weather.

@ 17 Dartigen: I’d think that that’d need to be a massive flare indeed (something on the order of Larry Niven’s “Inconstant Moon”) to do that. Satellites are affected by flares and CMEs directly in various ways, from orbital decay due to atmospheric expansion to induced currents that fry their circuitry to plain-ol’ brute-force x-ray radiation. Solar activity can also affect the ionosphere, which could cause interference between satellites and the ground.
I could be wrong, but I’d think that any solar activity powerful enough to disrupt wi-fi and similar wireless tech on the ground would have already brought down the world’s power grids. No one needs wi-fi when you have no power (and no internet).

I looked for the northern lights last night…we often see them from this location when the sun is active even if it is only a blue glow coming up above the trees. No luck though. Of course it was Valentine’s Day and I was expected elsewhere so couldn’t spend a whole lot of time outside–and when temps are below -25 C, it can be difficult to persuade that special someone to sit outside with me.